There is an ever increasing demand for effective electrical shielding of electrical connectors in view of the continuing complexity and miniaturization of communication devices which are affected by electromagnetic and radio frequency interference.
Such shielded connectors must be capable of manufacture and assembly with economical methods which are capable of adaptation to standardized connector configurations and sizes. Most such connectors include shield means which are readily stamped and formed from metal material complementary in shape to the profile of the shielded connector components. An example of a standardized connector configuration is a D-sub connector.
Furthermore, such shielded connectors are interengaged with a multiconductor electrical cable which, itself, has shielding means such as a braided shield inside an outer insulating jacket of the cable. The shield of the cable should be conductively coupled to the shield means of the connector. This most often is carried out by cable clamping means, such as a metal crimp barrel which is crimped onto the shielding braid of the cable. For economic manufacture and assembly purposes, the crimp barrel often is formed integral with the stamped and formed shield means of the connector, at a rear end thereof.
Whereas the shield means for the electrical connector is stamped and formed from metal material, heretofore the crimp barrel most often has been formed by a drawing process or at least partially drawn. There are distinct disadvantages of having a drawn portion of a shielding component of an electrical connector. First, the drawing process requires a thicker sheet of metal since drawing tends to thin the metal at the drawn areas. Second, the drawing process usually requires a triangular rather than a rectangular shape of the shielding component. In other words, the rear end of the shielding means angles toward the crimped cable on both sides thereof. When the connector components are overmolded with plastic material, the triangular shape requires the rectangular plastic overmold to fill large voids created by the tapered rear end of the shield. Third, a drawn crimp barrel is stiffer at the interface between the barrel and the rear end of the shield. Therefore, the actual crimping portion of the barrel usually is located rearwardly of the stiffer area of the barrel, requiring that the barrel be of an undue length. This is disadvantageous where miniaturization is a premium. In instances where there are size or envelope limitations, the drawn barrel provides a smaller transition section which makes the routing of the conductors between the terminals (often insulation displacement terminals) and the barrel more difficult.
This invention is directed to solving the above problems by providing a shield means with a new and improved stamped and formed cable clamping means or crimp barrel.